How Does Radon Get Inside Your Home?

What causes radon in home

There are many dangers that may be lurking inside our homes. Many of which we can identify with our senses – we can see, touch, or smell them. However, there are some dangers that are not so easy to detect. One of these dangers is radon gas.

Radon is a naturally occurring radioactive gas that is produced from the breakdown of uranium in rocks and soil. It is odorless, tasteless, and colorless, making it difficult to detect without the use of specialized equipment. 

While radon is a naturally occurring gas, it can become dangerous when trapped in enclosed spaces, such as our homes. Exposure to high radon levels over time can lead to serious health problems. In fact, according to the Environmental Protection Agency (EPA), radon exposure is the leading cause of lung cancer among non-smokers in the United States. 

But how does radon gas actually get inside our homes? Here’s what you need to know:

What Causes Radon Exposure?

Before we can understand how radon enters our homes, it’s important to know what causes radon exposure in the first place. 

As mentioned earlier, radon is a naturally occurring gas that is created from the breakdown of uranium, which is found in small amounts in most soils and rocks. This means radon gas is present in the ground all around us, including underneath and around our homes. 

How radon gas enter your home

As radon decays, it releases tiny radioactive particles into the air that can be inhaled. These particles are what make radon exposure dangerous to our health because they can damage the cells in our lungs, potentially leading to lung cancer.

Entry Points for Radon

While radon can be found in outdoor air, it becomes a problem when it enters and accumulates inside our homes. The EPA estimates that nearly one out of every 15 homes in the United States have elevated radon levels. 

So, how does radon gas enter our homes? Here are some common entry points:

1. Cracks in the Foundation

Basement floor crack

Radon is present in the ground, so it can easily seep through cracks and gaps in your home’s foundation. This is especially true for homes with unfinished basements, as the ground underneath is often exposed and has direct contact with the foundation.

Even small cracks or gaps can allow radon to enter, which then becomes trapped inside your home. As the gas continues to seep in, it can accumulate and reach a dangerous radon level over time. 

2. Gaps Around Service Pipes

Gaps around service pipes

Another common entry point for radon is through gaps around service pipes that enter your home. These pipes, such as water and sewer lines, often have small openings where they enter the foundation. These gaps can be large enough for radon to pass through and enter your home.

3. Gaps in Suspended Floors

Gaps in crawlspaces

Suspended floors, such as those found in crawl spaces, can also present a pathway for an indoor radon problem. These types of floors are often built with gaps and openings for ventilation. However, these openings can also allow radon to enter and become trapped inside the home. 

4. Cavities Inside Walls

Cavities inside wall

Even if your home’s foundation is free of cracks and gaps, radon can still find its way through cavities inside walls. These cavities can be created by plumbing, electrical wiring, or any other type of service line that runs through the walls. If these cavities are not properly sealed, high levels of radon can seep through and contaminate the indoor air. 

5. Construction Joints

Construction joints

Construction joints, where different building materials meet, can also be an entry point for radon. These joints often have small openings and gaps that are not properly sealed during construction. Over time, these seals can break down or deteriorate, allowing radon to enter.

6. Water Supply

Radon in water supply

If your water source comes from a well, it is important to have it tested for radon. Radon can dissolve in water and be carried into your home through your water supply. While most of the radon will evaporate once the water is exposed to air, some may still remain and contribute to high indoor radon levels.

It is recommended that your well water is tested every year to ensure the safety of your drinking water. 

Testing for Radon Gas

The only way to know if your home has elevated levels of radon is to test for it.

There are two main types of home radon testing: short-term and long-term. 

Short-Term Radon Tests

Radon testing canister kits

Short-term tests are a quick and simple way to get a general idea of the radon levels in your home. They can be purchased online and come with instructions for use.  

These tests usually involve placing a small device in the lowest livable area of your home, such as a basement or first floor. The device collects air samples and should be left undisturbed for the duration of the test. After the allotted time, the device is sent to a lab for analysis.  The whole process typically takes between 3 to 7 days to complete. 

Long-Term Radon Tests

Continuous radon monitoring

Long-term tests provide a more accurate and comprehensive measurement of radon levels in your home. These tests are typically conducted over a period of 90 days or longer and can be purchased online. 

Similar to short-term tests, long-term tests involve placing a device in the lowest livable area of your home and leaving it undisturbed for the duration of the test. However, these tests can also give a more accurate representation of the seasonal variations in radon levels. 

When to Hire Certified Radon Professionals?

If you are unsure about testing for radon on your own, or if you want a more accurate and reliable test, you can hire a certified radon professional. These professionals have the proper training and equipment to conduct thorough radon tests in your home.

They will use specialized devices such as charcoal canisters to collect samples. After the testing is completed, they will provide you with detailed results and recommendations for addressing any high levels of radon in your home. Typically, these professionals will also offer mitigation services to help reduce radon levels in your home.


As you can see, radon testing and mitigation are important steps in ensuring the safety of your home and family. With proper testing methods and the assistance of certified professionals, you can accurately assess the levels of radon in your home and take necessary steps to reduce them if needed. 

At Certified Environmental Contractors, we offer comprehensive radon testing and mitigation services to help keep your home safe. Our team of experienced professionals is trained and certified to handle all aspects of radon testing and mitigation, providing you with peace of mind. 

Contact us today to learn more!

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Peter Lordy

Peter Lordy is a seasoned environmental expert with over 30 years of experience in Superfund, industrial/commercial, residential site evaluations, and regulatory compliance including RCRA and CERCLA. He is a trained asbestos removal supervisor, holding various licenses from NJDEP for closure, subsurface, and tank testing. As a Rutgers-trained hazmat trainer, he possesses the required 40 hours of training for annual certification, alongside being Roth Certified. Peter is also a voting member of ASTM International and a Radon Measurement Specialist, demonstrating his broad expertise and commitment to environmental safety and standards.